The overall objective of this project is to evaluate the effectiveness of barbiturate coma in reducing the acute and long-term manifestations of severe perinatal asphyxia. This will be accomplished by: 1) Comparing a group of asphyxiated neonates receiving standard medical therapy with those receiving early treatment with thiopental. Immediate outcome in terms of the frequency and degree of intracranial hypertension and occurrence of the acute neurologic manifestations of asphyxia will be compared between these groups; 2) Determining the incidence of neurologic sequelae in treatment and control groups by means of long-term developmental follow-up. This will be accomplished by developmental testing at 3, 6, 12, 18, 24, 36, and 48 months of age; 3) Determining the pharmacokinetic properties of thiopental in the asphyxiated neonate. This will be done by measuring serum thiopental levels at various times after the therapy is started.